Properties of polymer materials

Usually, crystallization of flexible-chain polymers from undeformed solutions and melts involves chain folding. Spherulite structures without a preferred orientation are generally formed. The structure of the sample as a whole is isotropic it is a system with a large number of folded-chain crystals distributed in an amorphous matrix and connected by a small number of tie chains (and an even smaller number of strained chains called loaded chains). In this case, the mechanical properties of polymer materials are determined by the small number of these ties and, hence, the tensile strength and elastic moduli of these polymers are not high. 

As mentioned previously, chemistry and physico-chemistry play major roles in polymer microstructure, and, as a consequence, on polymer properties. The characterisation of several chemical parameters of polymer chains is thus of paramount importance for controlling the final properties of polymer materials... 

Changes in the properties of polymer materials caused by absorption of high-energy radiation result from a variety of chemical reactions subsequent to the initial ionization and excitation. A number of experimental procedures may be used to measure, directly or indirectly, the radiation chemical yields for these reactions. The chemical structure of the polymer molecule is the main determinant of the nature and extent of the radiation degradation, but there are many other parameters which influence the behaviour of any polymer material when subjected to high-energy radiation. 

The properties of polymer materials can e greatly extended by blending two or more homopolymers together. Blends may be classified as compatible or incompatible - although this does depend on the dimensions being considered. Compatibility is influenced by the molecular weight of the homopolymers and is enhanced in practice by incorporation of block copolymers and other compatibilizers. The effects of radiation on blends depend on the degree of compatibility and the extent of inter-molecular interaction (physically and chemically) between the different types of homopolymers. 

Heeger, A.J. in Heeger, A.J., Orenstein, J., Ulrich, D.R., Eds., Materials Research Society Proceedings, Vol. 109, Nonlinear Optical Properties of Polymers, Materials Research Society Pittsburgh, PA, 1988. 

Albertsson A-C, R nby B (1979) IUPAC International symposium on long-term properties of polymer materials. Stockholm, Sweden. Appl Polym Symp 35 423... 

The available data on the mechanical properties of polymer materials at cryogenic temperatures have been reported for the last few decades mainly in close connection with space technology. 

Heeger AJ, Orenstein J and Ulrich DR (Eds), "Nonlinear Optical Properties of Polymers", Materials Res Soc Symposium Proceedings, Vol. 109, Pittsburgh, 1988. 

The problem of the relationship between the equilibrium and the kinetic rigidity of the chain is of paramount importance since both the behavior of a chain molecule in solution and the main properties of polymer materials are related to these molecular characteristics. 

Crist B (1993). In Structure and Properties of Polymers, Materials Science and Technology, Vol 12, Thomas EL (ed), VCH Publishers, New York. 

Taken together, the new NMR methods enable studies of almost any dynamic process in polymers, and promise to contribute significantly to an improved understanding of the relations between chain motions and macroscopic—in particular mechanical—properties of polymer materials. 

While selecting modifier it is necessary to consider compatibility of the additive with polymer, volatility and extraction, dyeabilify, toxicity, odour, economical efficiency, effect on technological mode of processing, service properties of polymer materials. 

The principles of spatial resolution and contrast in NMR imaging have been presented in this chapter. An overview of selected applications of NMR to investigations of fluid systems, technical elastomers and rigid polymers has been given. The examples chosen demonstrate the potential of NMR for measurement of macroscopic properties of polymer materials. The importance of developments of NMR methods and equipment for materials science applications was underlined by example of the NMR MOUSE. 

Segmental mobility of polymer chains is one of the important properties of polymer materials. It has intimate relations to several physical properties of polymer materials. NMR relaxation measurements are wellknown as powerful techniques for elucidating the segmental motions of polymer materials not only in solution but also in the solid state. 

Figovsky, O., and Romm, F. Improvement of Anti-Corrosion Protection Properties of Polymer Materials, Anti-corrosion Methods Materials 45, no. 3 (1998) 312-330. 

Vasilets, VN. (2005), Modification of Physical Chemical and Biological Properties of Polymer Materials Using Gas-Discharge Plasma and Vacuum Ultraviolet Radiation, Dr. Sci. Dissertation, Institute of Energy Problems of Chemical Physics, Russian Academy of Sciences, Moscow. 

Electrical polarization is a fundamental property of polymer materials transformed into electrets in electrical fields [86-88]. Electrical polarization is used to promote adhesion between layers of antirust film materials, limit permeability of the layers, impede wetting, reduce waterproof properties, raise the quality of printing and intensify Cl saturation [68,70,88]. 

The considered electrochemical model has brought us to certain conclusions on the mechanism of polymer polarization in the M1-P-M2 systems. It is evident that definite electrode potentials are established on metals faces in contact with the polymer material. These potential values are affected by the work function of the electrons and metal afEnity to the corresponding structural elements of the polymer lining. These potentials are noncoincident with a standard electrochemical series of metals. This is natural, since the properties of polymer materials as electrolytes are not identical to those of salt solutions of the corresponding metals, for which the standard electrode potentials of metals are determined. The studied metals in pairs separated by the PVB lining are arranged in the following series ... 

The introduction of mineral or polymer filler into polymers is done to serve multiple purposes [339]. One of the essential effects of the filler particles is regulation of the structure formation process [340]. That is, the dispersed filler is used to create artificial structure formation centers. It has been demonstrated in practice that in most cases the optimal physical and mechanical properties of polymer materials are achieved when their structure comprises fine-scale and homogeneous elements. One of the factors for production of homogeneous structure... 

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